珠海城郊草地通量源区分析

Flux footprint analysis of suburban lawn in Zhuhai City

运用FSAM(Flux Source Area Model)模型对中山大学珠海校区综合气象观测场内涡度观测塔不同稳定度、不同时间尺度的通量源区进行分析。结果表明:(1)研究区盛行东南风,东南方向的通量数据占48.36%。(2)在90%贡献水平下,不同大气稳定度的通量源区变化范围各不相同。大气处于稳定状态下的通量源区范围较不稳定状态下大,其通量源区距观测塔最远距离可达155 m。(3)不同季节通量源区的大小也存在明显变化。当大气稳定时通量源区的大小关系为:冬>秋>春>夏;而在大气不稳定的条件下,春、秋季节通量源区大小没有明显区别。(4)白天通量源区范围较夜间小,在12:00时观测塔所能观测到的最远距离最小,为31 m。此外,不同下垫面、不同观测高度、不同通量贡献水平(P)等都会影响通量源区的大小。由FSAM模型基本可以较准确反映珠海城郊草地的通量源区大小。

By using the Flux Source Area Model （ FSAM ）, the flux source area of suburban lawn inZhuhai City was analyzed under different stability and different time scales. The results are shown as fol-lows ：① The southeast wind is prevailing with a ercentage of 48. 3 6 % .② Ulevel , the area of flux source varies with atmospheric stability , there are much larger areas of flux source, up to 155 m, in stable atmosphere.③ The area of flux source obviously changes with the seasons. Thearea of flux source changes from large to small in the order of winter, autumn, sthe stable atmosphere, while it does not change in spring and autumn under the unstable atmosphere. ④ The area of flux source is smaller in day time than in the night. The minimum visual distance of 31m was obtained at 12＊ 00. In addition, the area of flux source could be influenced by underlying surface, obser-vation height and contribution level （P）. Therefore, FSAM was considered as model t theflux source area of the suburban lawn in Zhuhai City.